High tension electric switch



26, 1943- T. F. JOHNSON 2,333,011

HIGH TENSION ELECTRIC SWITCH Filed May 16, 1941 2 Sheets-Sheet 1 06L 1943- T. F. JOHNSON 2,333,011

HIGH TENSION ELECTRIC SWITCH FiledMay 16, 1941 2 Sheets-Sheet 2 a 4 59 Wifi I inventionrelates to "high tension electric showing the switch blade and associated parts;

Patented Oct. 26, 1943 j, 2 ,333,011 I menreNsIoNEnLEo -iaroswrrcn omen f. Fortfjohnsoin, AtlantmlGa.

switches and, among ot-herobjects; aimsto pro- .vide a greatly improved switch of"the"rock ing insulator type Scbohstructed as to =permit the blade tip tohave" compound longitudinal and swinging niovement an'd coacting'with -a high pressurecontact provided with a'sleet hood. 1

Other aims andfadvahtages of the invention will appear in the specificatiomi when considered in connection with the accompanying drawings,

wherein:

Fig. l is aside elevation of a switch unit of the rocking'insulator type embodying the invention;

Fig. 2 is a fragmentary top plan view of Fig. 1

Fig. 3 is a fragmentary side elevation similar to Fig. i but showing the switch blade in a different position;

Fig. 4 is a fragmentary, enlarged horizontal sectional view talrenjon the line 4-4 of Fig. 3; and

Fig. 5 is a fragmentary, enlarged vertical sectional view taken on-the line 5-5 of Fig. 3.

Heretofore, air-break switches of the rocking type usually have had their switch blades rigidly mounted on a rocking insulator with the result that, when the insulator is rocked, the tip'of the switch blade swings in a true arc. The tip, being the point farthest fromthe pivot point of the insulator requires the maximum power to release it from the switch jaws. Also, the jaws must be open at the top to permit the tip to swing to open and closed positions. The present invention provides a novel arrangement in which a rigid switch blade is pivotally mounted at its rear end on the rocking insulator so that the tip of the blade moves longitudinally out of the jaws and swings upwardly in an arc and vice versa. This construction requires less power to operate the switch and permits greater spring pressure to be used on the jaws.

Referring particularly to the drawings, the switch structure is shown as being mounted on an ordinary structural channel It carrying a stationary insulator l l at one end on which ordinary floating spring contacts or jaws I? having a terminal i3, are mounted. A rocking insulator l4 having a conventional operating arm I5 is mounted on the channel intermediate its ends and carries a switch blade assembly H5 cooperating with the contacts [2. A third insulator I! is mounted on the other end of the channel and carries a conventional terminal l8, as well as the rear end of the usual articulated conductor 1 9.

The blade assembly I6 is here shown as comprising a blade carrier 2t having upwardly bent "ApplicatiortMay16;1941fSerialNo. 393,823 Q i Claimi. (01. 200-48)}; v y, e

spaced ears Z lat-itsrear'end mountedohapivot.

pin- 22 carried by an-upstandingwebi23.on;a plate.

24 secured to the cap of the :rocking insulator-14;; A" blade 25 is secured to the iorward end .of. the

blade carrier and'is shown. as being. composed of a pair of strap a. metal members 2 3 preferably made of copper. Their forward ends are secured together formir ig the blade tip-21 and their-rear;

endsarespaced apart to straddle the forwardi end portion or tongue of the blade carrier 20 to which they are shown as being secured by bolts When the switch is in closed position, the blade is supported substantially horizontally on a ledge 29 forming part of the sleet housing and support 30 for the jaws. The ledge 29 also serves to guide the blade tip 21 longitudinally into and out of the jaws l2. The rocking insulator I4 is limited in its swinging movement to stop the blade in that position by an adjustable stop member 3| carried by the insulator and arranged to strike a buffer or spring plate 32 on the channel support (Fig. 1) The blade is biased against the ledge 29 by coiled springs 33 connected to a cross rod 34 extending between the ears 2| and to the opposite sides of the web 23.

As the insulator I4 is rocked initially rearwardly, the rear end of the blade carrier swings counterclockwise; while the tip of the blade moves substantially longitudinally to the left, being prevented from moving upwardly due to the frictional engagement of the spring jaws I 2 and the tension of the springs 33. As the rearward movement of the insulator continues, a lug 35 on the bottom of the blade carrier strikes an adjustable stop 36 carried by a forward extension on the plate 24. At this point, as best shown in Fig. 3, the extreme forward end of the tip 21 has moved rearwardly sufiiciently to clear the rear end of the top wall of the sleet hood or housing 30. The

. blade assembly l6 and insulator 14 will then swing as a unit to its fully open position, as indicated by dotted lines in Fig. 1.

In order that arcing horns may be employed to cooperate with the usual arcing rod 31, the plate 24 is shown as having a horn-shaped bracket 38 extending upwardly and forwardly around the upper rear end of the blade carrier to which the horns 39 are secured. Incidentally, the bracket has lateral reinforcing flanges 40 above the'pivoted end of the blade carrier which also, serve as a sleet hood. The forward end of the articulated conductor I9 is also shown as being pivotally connected to the bracket 38 and flexible cables 4| are shown as being connected to the blade members 26 and to the conductor l9.

When the insulator I4 is rocked clockwise, to close the switch, the blade 25 moves with it as a unit until the bottom front edge of the blade tip 21 strikes the top surface of the ledge 29 (Fig. 3). Continued clockwise movement causes the insulator l4 and the rear pivoted end of the blade carrier 20 to swing in an arch, while the tip 2142f the blade, supported onthe ledge 29, is forced substantially longitudinallyintothe spring jaws l2.

The blade carrier 20 is shown as having an upstanding stop lug 42 spaced slightly beneath the overhanging portion of the bracket 38' when. the switch is in closed position (Fig. 1).

This lug is adapted. to strike the bracket 38 and limit tion, a rocking insulator; a rigid switch blade pivoted for limited swinging movement on said rocking insulator; a stationary insulator; a jaw the upward movement of the blade carrier 20] relative to the bracket when the switch is: in

open position to prevent the springs 33 from being overstretchedand also to prevent the blade from damaging the horns .39, due to handling while the switch is being assembled or installed.

From the foregoing description, it will be seen that the improved switch permits a powerful and positive electricalconnection between the blade tip and the jaws. ,I'he mechanism is extremely rugged and simple in its construction.

Snow orv ice, cannot interfere with the operahousing on said stationary insulator'having a closed top; a stop member for the blade to arrest its swinging movement as the rocking insulator swings the blade toward closing position but permitting the tip to slide longitudinally thereon betweenthe contacts and beneath the top of the housing during the final switch closing movement; a horn-shaped bracket car ried by the rocking insulator having lateral flanges overlying the pivoted end of the switch blade to provide a sleet hood therefor; and arc: ing' horns carried by said bracket.

TOMLINSON FORT JOHNSON. 

